TY - GEN
T1 - A numerical study of conjugate heat transfer by natural convection and surface radiation in a square enclosure with thick adiabatic walls
AU - Hadim, H.
AU - Blecker, K.
PY - 2013
Y1 - 2013
N2 - A numerical solution of heat transfer by combined natural convection and surface radiation in a square enclosure with thick adiabatic top and bottom walls and isothermal vertical walls is presented. The present model was used to obtain new results with the addition of thermal conduction at the thick top and bottom walls for a thermal conductivity ratio, K=ksolid/k fluid, that ranges from 0 to 10, emissivity of the adiabatic walls that ranges from 0 to 1, and the Rayleigh Number that ranges from 103 to 106. The model was validated by comparing the results to a benchmark solution and other solutions found in the literature. The results showed that with an increase in thermal conductivity ratio, the flow circulation decreases while the average Nusselt Number increases indicating increased heat transfer across the thick walls and the fluid in the corners. The results indicate that while past studies have shown negligible impact of the emissivity of the adiabatic walls on characteristics of the flow and heat transfer within the cavity, when a wall with moderate heat capacity and conductivity is considered, the resulting flow velocity and temperature distribution within the cavity are found to be significantly influenced by the thick wall emissivity. As the conductivity ratio increases this discrepancy between thin and thick walls becomes greater, there is further need for a more complex and accurate model including the thick walls. The results also showed that an increase in the emissivity of the adiabatic walls results in a slight decrease in the average Nusselt Number.
AB - A numerical solution of heat transfer by combined natural convection and surface radiation in a square enclosure with thick adiabatic top and bottom walls and isothermal vertical walls is presented. The present model was used to obtain new results with the addition of thermal conduction at the thick top and bottom walls for a thermal conductivity ratio, K=ksolid/k fluid, that ranges from 0 to 10, emissivity of the adiabatic walls that ranges from 0 to 1, and the Rayleigh Number that ranges from 103 to 106. The model was validated by comparing the results to a benchmark solution and other solutions found in the literature. The results showed that with an increase in thermal conductivity ratio, the flow circulation decreases while the average Nusselt Number increases indicating increased heat transfer across the thick walls and the fluid in the corners. The results indicate that while past studies have shown negligible impact of the emissivity of the adiabatic walls on characteristics of the flow and heat transfer within the cavity, when a wall with moderate heat capacity and conductivity is considered, the resulting flow velocity and temperature distribution within the cavity are found to be significantly influenced by the thick wall emissivity. As the conductivity ratio increases this discrepancy between thin and thick walls becomes greater, there is further need for a more complex and accurate model including the thick walls. The results also showed that an increase in the emissivity of the adiabatic walls results in a slight decrease in the average Nusselt Number.
KW - Conduction
KW - Conjugate heat transfer
KW - Enclosure
KW - Natural convection
KW - Thermal radiation
UR - http://www.scopus.com/inward/record.url?scp=84903458734&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84903458734&partnerID=8YFLogxK
U2 - 10.1115/IMECE2013-63668
DO - 10.1115/IMECE2013-63668
M3 - Conference contribution
AN - SCOPUS:84903458734
SN - 9780791856345
T3 - ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)
BT - Heat Transfer and Thermal Engineering
T2 - ASME 2013 International Mechanical Engineering Congress and Exposition, IMECE 2013
Y2 - 15 November 2013 through 21 November 2013
ER -